1. Field of the Invention
The present invention relates to a vehicle door latch device, and in particular to a latch device provided with power closing and power opening mechanisms of a door (including a hinged passenger door, a trunk lid, a glass hitch, a tailgate and the like).
2. Description of the Related Art
Conventionally, a door latch device provided with both a power closing mechanism and a power opening mechanism has been known. The known power closing mechanism causes a latch to be rotated to a full-latched position by a motor power after the latch is rotated to a half-latched position through engagement with a striker so that a door is displaced from a half-latched state to a full-latched state. Also, the known power opening mechanism causes the latch to be free to rotate by releasing a ratchet from the latch with a motor power.
A problem in such a conventional door latch device lies in that each of the power closing and the power opening mechanisms has own motor. Using two motors causes increase in cost of the latch device and increase in weight thereof.
Further, the vehicle door latch device provided with the power closing mechanism is conventionally provided with a safety mechanism which stops or invalidates operation of the power closing mechanism. The safety mechanism is provided with a function for releasing a connected state between the latch and the motor and a function for releasing the ratchet from the latch.
There is a drawback that the conventional safety mechanism is complicated and is increased in the number of parts.
In view of the above circumstances, an object of the present invention is to provide a door latch device where a power closing mechanism and a power opening mechanism can be operated by only one common motor. Since the power closing mechanism and the power opening mechanism shares one common motor, the door latch device of the present invention can be manufactured inexpensively in a small size and in a reduced weight.
Also, another object of the present invention is to provide a door latch device with a simplified structure, which stops or invalidates operation of a power closing mechanism.